Diabetics must monitor their own blood glucose levels, often several times a day, to determine how far above or below a normal level their glucose level is and to determine what oral medications or insulin(s) they may need. This is often done by placing a drop of blood from a skin prick onto a glucose strip and then inserting the strip into a glucose meter, which is a small machine that provides a digital readout of the blood glucose level.
Recently, continuous glucose monitoring systems (CGMS) have been developed that continuously record a patient's glucose levels throughout the day. Generally speaking, these devices work by inserting a small sensor into subcutaneous tissues. The sensor measures the level of glucose in the tissue and sends this information to a monitor worn by the patient which stores the results, In order to determine blood glucose levels, the monitor must be calibrated daily by entering at least three blood glucose readings obtained at different times, using a standard blood glucose meter. For example, Medtronic, Inc. of Minneapolis, Minn., sells an approved MinMed® device which can provide up to 288 glucose measurements every 24 hours for up to 72 hours.
One problem with the blood glucose level data obtained from continuous glucose monitoring systems is that there is a lot of variability in the data. The glucose level data shows a lot of sharp fluctuations, or signal noise, that is most likely not indicative of the average blood glucose levels, but rather is likely due to variability in the measurements.
Because of the lack of accurate diary data from patients and the lack of mealtime synchronization, another problem with CGMS data is the inability to aggregate the data easily to facilitate treatment group comparisons and to visualize the average treatment group curves.
As a result of the problems indicated above, a further problem is the lack of CGMS data indicators that would be useful for diagnosing and treating hypoglycemia and diabetes.
Therefore, there is a need to aggregate continuous blood glucose level data and to identify prognostic indicators for diagnosing and treating hypoglycemia and diabetes.